title: The deubiquitinating enzyme AMSH1 and the ESCRT-III subunit VPS2.1 are required for autophagic degradation in Arabidopsis.
abstract: In eukaryotes, posttranslational modification by ubiquitin regulates the activity and stability of many proteins and thus influences a variety of developmental processes as well as environmental responses. Ubiquitination also plays a critical role in intracellular trafficking by serving as a signal for endocytosis. We have previously shown that the Arabidopsis thaliana associated molecule with the SH3 domain of STAM3 (AMSH3) is a deubiquitinating enzyme (DUB) that interacts with endosomal complex required for transport-III (ESCRT-III) and is essential for intracellular transport and vacuole biogenesis. However, physiological functions of AMSH3 in the context of its ESCRT-III interaction are not well understood due to the severe seedling lethal phenotype of its null mutant. In this article, we show that Arabidopsis AMSH1, an AMSH3-related DUB, interacts with the ESCRT-III subunit vacuolar protein sorting2.1 (VPS2.1) and that impairment of both AMSH1 and VPS2.1 causes early senescence and hypersensitivity to artificial carbon starvation in the dark similar to previously reported autophagy mutants. Consistent with this, both mutants accumulate autophagosome markers and accumulate less autophagic bodies in the vacuole. Taken together, our results demonstrate that AMSH1 and the ESCRT-III-subunit VPS2.1 are important for autophagic degradation and autophagy-mediated physiological processes.
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany.
authors.forename: Anthi
authors.initials: A
authors.lastname: Katsiarimpa
authors.forename: Kamila
authors.initials: K
authors.lastname: Kalinowska
authors.forename: Franziska
authors.initials: F
authors.lastname: Anzenberger
authors.forename: Corina
authors.initials: C
authors.lastname: Weis
authors.forename: Maya
authors.initials: M
authors.lastname: Ostertag
authors.forename: Chie
authors.initials: C
authors.lastname: Tsutsumi
authors.forename: Claus
authors.initials: C
authors.lastname: Schwechheimer
authors.forename: Frédéric
authors.initials: F
authors.lastname: Brunner
authors.forename: Ralph
authors.initials: R
authors.lastname: Hückelhoven
authors.forename: Erika
authors.initials: E
authors.lastname: Isono
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001343:Autophagy / Q000235:genetics*; D003624:Darkness; D060467:Disease Resistance / Q000235:genetics; D004705:Endocytosis / Q000235:genetics; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics* / Q000378:metabolism; D005658:Fungi / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D018613:Microscopy, Confocal; D009154:Mutation; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D030821:Plants, Genetically Modified; D011485:Protein Binding; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D064570:Ubiquitin-Specific Proteases / Q000235:genetics / Q000378:metabolism; D057149:Ubiquitinated Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D021122:Protein Subunits; D057149:Ubiquitinated Proteins; C576222:VPS2.1 protein, Arabidopsis; D049452:Green Fluorescent Proteins; D064570:Ubiquitin-Specific Proteases; C586775:AMSH1 protein, Arabidopsis; C586776:AMSH3 protein, Arabidopsis